phosphor-host-postd: disable tests

Compiling the tests isn't needed for a basic build, and can lead to
build failures due to not having gmock/gtest headers.

Signed-off-by: Zev Weiss <zev@bewilderbeest.net>
Change-Id: I0d55e8a19260dde7dc7f06831d168a1091dc4e74
diff --git a/meta-phosphor/recipes-phosphor/host/phosphor-host-postd_git.bb b/meta-phosphor/recipes-phosphor/host/phosphor-host-postd_git.bb
index 8fa29eb..0402784 100644
--- a/meta-phosphor/recipes-phosphor/host/phosphor-host-postd_git.bb
+++ b/meta-phosphor/recipes-phosphor/host/phosphor-host-postd_git.bb
@@ -33,6 +33,7 @@
     -Dsnoop-device=${SNOOP_DEVICE} \
     -Dpost-code-bytes=${POST_CODE_BYTES} \
     -Dsystemd-target=multi-user.target \
+    -Dtests=disabled \
 "
 
 POSTCODE_SEVENSEG_DEVICE ?= "seven_seg_disp_val"